Omnidirectional composite right/left-handed leaky-wave antenna with downtilted beam

In this study, we propose a novel leaky-wave omnidirectional antenna using a coplanar-strip-type composite right/left-handed (CRLH) line for application to a base station antenna used for a mobile communication system. Further, we realize an extremely slender omnidirectional antenna by adopting a polarization composite method. We also design a prototype antenna in the 3.5 GHz band and show the results of measurement obtained using this prototype antenna.